Hi, On (Thu) 12 Jan 2012 [16:29:14], Linus Torvalds wrote: > On Wed, Jan 11, 2012 at 9:22 PM, Rusty Russell <rusty@xxxxxxxxxxxxxxx> wrote: > > > > Amit Shah (12): > > virtio: pci: switch to new PM API > > Hmm. Afaik, this is broken, or at least not complete. > > Sure, it switches to the new PM API, but it still does the PCI ops itself. > > It should not need to - the PCI layer will do the power state and > standard PCI device state saving. And setting the PCI_D3hot state when > shared interrupts can still happen at suspend time is just a bad idea. The idea behind this patchset is to get S4 working properly. There's no change to the way S3 was/is being done, and the state-setting is done only in the S3 PM callbacks. > So I think you're doing extra work and introducing bugs by doing so - > the default PCI bus operations should already do all you do, just do For S4, we need some driver-specific (not just virtio-specific) work to be done on the freeze/restore callbacks... > it better. And then you can use the SIMPLE_DEV_PM_OPS() to build the > dev_pm_ops structure and get all the normal cases right automatically. ... and we also have separate stuff to be done in thaw/restore/freeze callbacks for different drivers. So using the *_PM_OPS() macros wouldn't have worked. > I don't know if there is any particularly good example of this, but > you can see some of the network drivers for examples of this. Notice > how they don't need to worry about PCI power states etc at all, they > just need to worry about the actual chip suspend/resume (and for a > network driver, you'd do the netif_device_detach/netif_device_attach > etc) I think your concern is with the way S3 is being done, and I volunteer to look at improving the situation there. Might take a while, though. Amit _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
